1. Field of the Invention
The present invention relates to a vehicle electrical conduction path for use in hybrid vehicles, electric vehicles and the like.
2. Description of the Related Art
Conventional vehicle electrical conduction paths for use in hybrid vehicles, electric vehicles and the like have been disclosed in JP-A-2004-171952 and JP-A-2007-87628.
JP-A-2004-171952 discloses a vehicle electrical conduction path having a plurality of electric cables collectively accommodated in a metallic pipe. The vehicle electrical conduction path is required to be held in a desired wiring shape (layout), for example at a lower surface of a vehicle body, as well as having a shield means, in view of an effect of noise on a device mounted on a vehicle or a control cable (herein referred to as the device mounted on the vehicle). JP-A-2004-171952 allows the noise on the device mounted on the vehicle to be inhibited by accommodating the plurality of the electric cables in the metallic pipe serving as the shield means, and the plurality of the electric cables to be held in the desired wiring shape by forming the metallic pipe into the desired wiring shape.
Also, JP-A-2007-87628 discloses a vehicle electrical conduction path having a control cable and an auxiliary power cable accommodated in an inner metallic pipe, and the inner metallic pipe with the control cable and the auxiliary power cable accommodated therein, and a main power cable accommodated in an outer metallic pipe. JP-A-2007-87628 can, as with JP-A-2004-171952, hold a desired wiring shape (layout), and allows noise caused in the main power cable in which large current flows, to be inhibited from affecting electrical signals propagating in the control cable, because the inner metallic pipe serves as a shield for the control cable. Also, the outer metallic pipe can serve as a shield to inhibit the effect of noise caused in the main power cable in which large current flows, on the device mounted on the vehicle.
The vehicle electrical conduction paths are for connecting e.g. between a motor and an inverter, or between an inverter and a battery, in hybrid vehicles, electric vehicles and the like. For that, high voltage current flows in power cables of the vehicle electrical conduction paths connecting therebetween. These electrical conduction paths in which high voltage current flows are colored in a predetermined color (orange color for indicating high voltage portion) standardized in compliance with an international standard.
In JP-A-2004-171952 and JP-A-2007-87628, since the member positioned at the outermost layer is the metallic pipe, this metallic pipe is painted in the predetermined color. However, there arises the problem that this painting is very time-consuming and costly due to requiring heat resistance, and mechanical strength (adherence) causing no peeling during forming process, and also due to needing a good even coating in view of reliability thereof.
To save such labor in the painting, the inventors have contemplated accommodating the power cable and the control cable in a corrugated tube made of a resin colored beforehand. The corrugated tube is an accordion hollow tube, also called slit tube, flexible electrical conduit, etc.
When the power cable or the control cable is accommodated in the corrugated tube, there arises the problem, however, that the power cable and the control cable cannot be held in a desired wiring shape due to the flexibility of the corrugated tube.
The technique contemplated to overcome this problem and allow the power cable and the control cable to be held in a desired wiring shape is, for example, to accommodate the control cable with enhanced rigidity in the corrugated tube, form the control cable in the desired wiring shape, and lay the power cable along the control cable, thereby holding the vehicle electrical conduction path in the desired wiring shape.
Refer to JP-A-2004-171952, JP-A-2007-87628, and JP-A-2009-123635, for example.
A rigid structure of a vehicle electrical conduction path portion to be connected to a device mounted on a vehicle (herein referred to as the device) is not preferred because a cable break thereof is caused by stress due to vehicle vibration acting on the portion connecting the vehicle electrical conduction path and the device. For that, the vehicle electrical conduction path portion to be connected to the device needs to be structured to be flexible.
When the control cable with enhanced rigidity is accommodated in the corrugated tube as described above, there is therefore the problem that its portion to be connected to the device has to be very inconveniently reconnected to a flexible cable, and connected via the flexible cable to the device.